Which medication requires patients to maintain a stable, consistent intake of Vitamin K due to clotting interference?

Warfarin (Coumadin).

Patients prescribed anticoagulant medications, notably warfarin, often sold under the brand name Coumadin, must be highly conscious of their Vitamin K consumption. This necessity stems from the fundamental biological role Vitamin K plays in the liver's synthesis of several clotting factors required for blood coagulation. Warfarin functions by inhibiting the activation of these Vitamin K-dependent clotting factors. If a patient suddenly consumes a large amount of Vitamin K (such as after drastically increasing green bean consumption), it can counteract the intended therapeutic effect of the medication, potentially leading to dangerous blood clotting events. Therefore, the medical advice centers not on eliminating Vitamin K, but on achieving dietary consistency so that the dosage of the anticoagulant drug can be reliably calibrated.